A correction value calculating device that calculates a correction value for correcting an error in the eye gaze associated with the individual difference of an object person in detection of the eye gaze is known (for example refer to Patent Document 1). This correction value calculating device calculates the correction value on the basis of a first eye gaze vector that is calculated on the basis of a shot image of an eye of a subject and is directed from the eye toward a screen of a display device and a second eye gaze vector toward a point of gaze at which the subject is gazing, decided on the basis of the feature on a displayed image. For example, these techniques are disclosed in Japanese Laid-open Patent Publication No. 2011-217764, Japanese Laid-open Patent Publication No. 11-76165, and Japanese National Publication of International Patent Application No. 2013-524390.